The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Jennifer Perrottet - One of the best experts on this subject based on the ideXlab platform.
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Enabling unrestricted UAS airspace access: Performance based navigation
2017 Integrated Communications Navigation and Surveillance Conference (ICNS), 2017Co-Authors: Jennifer PerrottetAbstract:The goal of the integration of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is to achieve “file-and-fly” access to all classes of airspace. This means the UAS will fly without limitations or waivers in airspace shared with other manned and unmanned Aircraft. In the case of large UAS operating in a similar manner to Transport Category Aircraft in terminal, en-route and oceanic/remote environments, this includes the ability to perform area navigation. This paper explores the unique challenges of applying the concepts and requirements of Performance Based Navigation (PBN) to UAS. Some challenges include GNSS only navigation, Flight Management System (FMS) capable of flying ARINC 424 path terminators, PBN procedures tailored to UAS performance characteristics, and the ability of the UAS to perform instrument procedures during loss of link. Among these challenges includes the assumption that most UAS will be using GNSS only navigation. This is limiting because if GPS is unavailable, the UAS may be able to coast on inertial navigation for some time but then will be incapable of performing PBN. Also, while ARINC 424 path terminators are not necessarily required to perform PBN, procedure designers create routes and RNAV/RNP approaches under the assumption that operators have a capable FMS. A minimum set of path terminators must be defined in order to perform these procedures in the airspace environment of intended flight. In the case of lost link, careful consideration must be taken as to which path terminators will be housed within the ground station and/or onboard the Aircraft to ensure that safety and ability to perform PBN is maintained.
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Enabling unrestricted UAS airspace access: Performance based navigation
2017 Integrated Communications Navigation and Surveillance Conference (ICNS), 2017Co-Authors: Jennifer PerrottetAbstract:The goal of the integration of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is to achieve “file-and-fly” access to all classes of airspace. This means the UAS will fly without limitations or waivers in airspace shared with other manned and unmanned Aircraft. In the case of large UAS operating in a similar manner to Transport Category Aircraft in terminal, en-route and oceanic/remote environments, this includes the ability to perform area navigation.
Timothy T Takahashi - One of the best experts on this subject based on the ideXlab platform.
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prediction of wing structural mass for Transport Category Aircraft conceptual design
15th AIAA Aviation Technology Integration and Operations Conference, 2015Co-Authors: Timothy T Takahashi, Tyler LemondsAbstract:This paper describes the development of statistical semi-empirical relationships to help estimate the structural weight of wings, applicable to conventionally configured Transport Category Aircraft design. These models are based upon a wing primary structure weight derived from an optimizing beam-element formulation. The underlying beam-element method sizes primary structure based upon “envelope” inertial and aerodynamic loads arising from maneuvering flight and hard-landing conditions. It sizes structure cognizant of tensile yield, compression yield, compression buckling of the skins and compression buckling limitations of integrally stiffened wing covers. Because our primary structural weights are based upon physical geometry we capture “real world” design effects that escape lower order physics based and purely empirical methods. Our trends differ substantially on many accounts from those “famous” wing weight regressions based upon simple strength concerns.
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Reforming Field Performance Federal Aviation Regulations for Operational Safety and Consistency
SSRN Electronic Journal, 2014Co-Authors: Timothy T Takahashi, Andrew CreightonAbstract:This paper explores three regulations: 14 CFR § 25.113, 14 CFR § 25.125 and 14 CFR § 121.195 and their interactions with two other regulations: 14 CFR § 25.107, 14 CFR § 25.109. Together, these laws control the means by which takeoff and landing runway requirements of Transport Category Aircraft are computed. Inspection of airline pilot manuals and interviews with Transport pilots indicate that operational procedures are at odds with the design maxims given in popular textbooks. Because professional pilots fly using field performance guides based on ‘advisory’ data rather to distances prepared using the FAA ‘certified’ process, the authors recommend that the CFR be amended to reflect actual operational practices consistent with the current procedures contained within FAA published advisory circulars. Thus, FAA certified performance data would include performance on dry, wet, icy and other contaminated runways. Additionally, the manufacturers of four-engine Aircraft should be able to certify field performance utilizing two engines of reverse thrust during both rejected take-offs and standard landing events. These recommendations would imply revision to 14 CFR § 25.113, 14 CFR § 25.125 and 14 CFR § 121.195, defining available braking coefficients on contaminated runways as well as stating an approved procedure to deploy reverse thrust to assist wheel braking.
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regulatory changes to enable the development of more efficient Transport Category Aircraft
Journal of Aircraft, 2013Co-Authors: Timothy T TakahashiAbstract:This paper studies the history of cabin pressurization regulations and makes policy recommendations to amend them in a manner that would encourage the design of all-new Aircraft. One recently amended regulation (Code of Federal Regulations, Title 14, Sec. 25.841) has an unintended byproduct. The Federal Aviation Administration must grant a compliance waiver in order to certify a new Aircraft design with wing-mounted engines to fly at altitudes much above 40,000 ft. However, the Federal Aviation Administration grandfathers existing designs with higher certified ceilings and permits these designs to be modified under the Changed Product Rule (Code of Federal Regulations, Title 14, Sec. 21.101). Because all but the largest commercial Aircraft have their useful aerodynamic efficiency compromised if they are restricted to fly at or below 40,000 ft, the current regulation favors current production or derivative changes to existing certified Aircraft over the development of an all-new modern airframe. Additional...
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optimum transverse span loading for subsonic Transport Category Aircraft
Journal of Aircraft, 2012Co-Authors: Timothy T TakahashiAbstract:This study considers the overall system impact of the design transverse aerodynamic load distribution on future subsonic, Transport Category Aircraft. The fundamental question revisited here concerns wing design ground rules. Should the wing be designed to favor an aerodynamically optimal, “elliptical” transverse span load that minimizes induced drag? Or, should the wing be tailored to have a reduced root bending moment in order to save structural weight at some expense of increased drag? The problem is examined at three levels of technical scrutiny: from a qualitative, rational basis perspective; from a quantitative, intermediate-fidelity parametric performance perspective; and from the results of a quantitative, coupled multidisciplinary optimization trade. The quantitative tradesindicatethattailoringofthedesigntransverseloaddistributiontofavorareducedwingrootbendingmoment resultsinsomestructuralweightsavings,butattheexpenseofhigherdrag,increasedfuelconsumption,andreduced mission performance. These trades substantiate a different rational basis argument: a balancing test that will typically recommend the aerodynamically optimal design for all but the shortest-range Aircraft.
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law and engineering an alternative approach to develop more efficient Transport Category Aircraft
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Timothy T TakahashiAbstract:This paper studies the history of cabin pressurization regulations and makes policy recommendations to amend them in a manner that would encourage the design of all-new Aircraft. One recently amended regulation, 14 CFR § 25.841, has an unintended byproduct. It makes it extremely difficult for a new Aircraft design with wing-mounted engines to obtain a type-certificate to fly at altitudes much above 40,000 feet. However, the FAA grandfathers existing designs with higher certified ceilings and permits these designs to be modified under the Changed Product Rule, 14 CFR § 21.101. Because all but the largest commercial Aircraft have their useful aerodynamic efficiency compromised if they are restricted to fly at or below 40,000 feet, the current regulation favors current production or derivative changes to existing certified Aircraft over development of an all-new modern airframe. Additional changes to this regulation could encourage the design of a new generation of Aircraft with significantly lower fuel consumption. A proposed balancing address would address global environmental policy concerns against the foreseeable risks of sudden cabin depressurization.
Mayday - One of the best experts on this subject based on the ideXlab platform.
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Safety Topics: Type Inflation by Inert Gas
Aircraft Engineering and Aerospace Technology, 1993Co-Authors: MaydayAbstract:A final rule has been issued by the FAA that mandates what is already an existing industry practice, as required by airworthiness directive. This amendment to FAR's is based on NPRM 90–7 issued on March 5, 1990 which proposed to require that an inert gas, such as nitrogen, be used in lieu of air, for inflation of tyres on certain Transport Category Aircraft.
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Safety Topics: Improved Access Required
Aircraft Engineering and Aerospace Technology, 1992Co-Authors: MaydayAbstract:A final rule has been issued by the FAA which revises the regulations to require improved access to the Type III emergency exits (typically of the smaller overwing type) in Transport Category Aircraft with 60 or more passenger seats. These changes are the result of tests that were conducted at the FAA's Civil Areomedical Institute (CAMI) and are intended to improve the abililty of occupants to evacuate an Aircraft under emergency conditions. They affect air carriers and commercial operaters of Transport Category Aircraft as well as the manufacturers of such Aircraft.
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Safety Topics: Emergency Exits
Aircraft Engineering and Aerospace Technology, 1990Co-Authors: MaydayAbstract:PROPOSED rules by the FAA revise current requirements for the passenger emergency exits of Transport Category Aircraft as well as adopt two new exit types into the regulations. It is also proposed to reduce the maximum inflation time of an escape slide to reflect the current state‐of‐the‐art. These considerations result from recommendations made by a subgroup of the FAA's Design and Certification Group and follow on amendments to Part 23 FAR.
Thomas J Vukits - One of the best experts on this subject based on the ideXlab platform.
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overview and risk assessment of icing for Transport Category Aircraft and components
40th AIAA Aerospace Sciences Meeting & Exhibit, 2002Co-Authors: Thomas J VukitsAbstract:An overview of Aircraft icing and a risk assessment by Aircraft and Aircraft component type is presented with a focus on Federal Aviation Regulations Part 25 (Transport Category) Aircraft. Icing theory and pertinent parameters are reviewed. The frequencies of accidents by Aircraft type for a fifteen-year period are given. A risk assessment technique is applied to individual Aircraft components. Methods of lowering those risks are presented. Finally, a fairly extensive bibliography is categorically presented. Units NOMENCLATURE Term Definition _ CM Continuous Maximum (Stratiform Clouds) FAA Federal Aviation Administration FAR(s) Federal Aviation Regulation(s) Title 14 Code of Federal Regulations, Chapter 1 HT Horizontal Tail ICTS Ice Contaminated Tailplane Stall IM Intermittent Maximum (Cumuliform Clouds) IPS Ice Protection System(s) ISA International Standard Atmosphere KTAS Knots True Airspeed LWC Liquid Water Content MED Mean Effective Diameter MTOW Maximum Take-Off Weight MVD Median Volumetric Diameter NACA National Advisory Committee for Aeronautics NTSB National Transportation Safety Board RPM Revolutions Per Minute SLD Supercooled Large Droplets SLW Supercooled Liquid Water VT Vertical Tail % Percent *Senior Mechanical Engineer, Senior Member AIAA f Copyright © 2001 by Thomas J. Vukits. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. [knots] [g/m]
Graham Clark - One of the best experts on this subject based on the ideXlab platform.
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crashworthiness of isofix and latch child restraint systems in Transport Category Aircraft
27th International Congress Of The Aeronautical Sciences (ICAS), 2010Co-Authors: Adam Shrimpton, Graham ClarkAbstract:This paper describes progress in a research project which aims to analyse the crashworthiness of automotive child restraints in a typical Transport Category Aircraft seating configuration using a numerical dynamic analysis. The dynamic behaviour of child restraints and especially their effect on the safety of other passengers is not well known. The advent of new child restraint installation methods has elevated the need for a fast and reliable tool to enable the assessment of the crashworthiness of seating configurations involving child restraints.
